Various endovenous treatments are commonly used for treating venous reflux disease, and other diseases of hollow anatomical structures (HAS). Venous reflux disease is a disease caused by damaged vein valves, which typically prevent blood from flowing backwards in a vein. Thus, with damaged valves, particularly in the legs, gravity works against the blood flowing upward toward the heart, resulting in venous congestion and varicose veins. Varicose veins typically happen in superficial veins, such as the Greater Saphenous Vein (GSV) and the Lesser Saphenous Vein (LSV), creating unsightly and painful bulges and tortuous veins, and may lead to many serious complications.
Electrosurgical heating is one endovenous treatment for venous reflux disease, as well as other diseases in HAS. Electrosurgical heating may use radio frequency current to apply energy to create targeted tissue ablation to seal off damaged veins. Electrosurgical equipment typically includes a generator, such as an RF generator, and a catheter having a heating segment located at the distal end, which is inserted into the vein(s) during treatment. The heating segment may use RF energy driven by the RF generator to heat and seal the vein. Currently, the catheters include a heating segment having a fixed length, such as 7 cm, 4 cm, 3 cm, and a specific combination of length and diameter, for example, 7F on a 7 cm catheter, 5F on a 3 cm catheter, or 3F on a 1 cm catheter. (F indicates the French scale for measuring the outside diameter of a catheter, 1F=0.33 mm.)
However, the Saphenous Vein length and diameter varies at the thigh, calf and ankle portions and from patient to patient. For example, the Greater Saphenous Vein may range in diameter from about 2.5 to 14.0 mm at the femoral junction, 1.5 to 12.0 mm in the thigh, and 1.0 to 8.0 mm in the calf, while Lesser Saphenous Vein diameters may range from 1.5 to 3.0 mm. Often, there may be a need for treating these various sizes in a single patient in a single procedure.